Document the decision to assume that the cost of floats is twice as much as integers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179478 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/BasicTargetTransformInfo.cpp b/lib/CodeGen/BasicTargetTransformInfo.cpp
index 499571f..4a99184 100644
--- a/lib/CodeGen/BasicTargetTransformInfo.cpp
+++ b/lib/CodeGen/BasicTargetTransformInfo.cpp
@@ -205,11 +205,13 @@
std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(Ty);
bool IsFloat = Ty->getScalarType()->isFloatingPointTy();
+ // Assume that floating point arithmetic operations cost twice as much as
+ // integer operations.
unsigned OpCost = (IsFloat ? 2 : 1);
if (TLI->isOperationLegalOrPromote(ISD, LT.second)) {
// The operation is legal. Assume it costs 1.
- // If the type is split to multiple registers, assume that thre is some
+ // If the type is split to multiple registers, assume that there is some
// overhead to this.
// TODO: Once we have extract/insert subvector cost we need to use them.
if (LT.first > 1)